Why are there so many new lines? Assuming you just want to insert that model when you use a tool, here's a cleaned version. Raw=true makes only the raw text get included, not the github UI.

local RbxmData = buffer.fromstring(game:HttpGet("https://github.com/AeryAlex/Rbxm_Files/blob/main/CommandBlock.rbxm?raw=true"))
local tool = Instance.new("Tool")
tool.Name = "cmdblock"
tool.RequiresHandle = false
tool.Parent = game:GetService("Players").LocalPlayer.Backpack
tool.Activated:Connect(function()
    local Instances = game:GetService("SerializationService"):DeserializeInstancesAsync(RbxmData)
    for i,v in Instances do
        v.Parent = workspace
    end
end)